1. Field of the Invention
The present invention relates generally to the field of wireless communication, and particularly to the manufacturing of an antenna.
2. Description of Related Art
The precision on the physical dimensions of an antenna is dictated by its bandwidth compared to the targeted application""s bandwidth. In the case of very high Q antennas such as the magnetic dipole antenna (MDA) (may be extended to capacitively loaded antennas), these tolerances can lead to structures non manufacturable at high volume. A rough xe2x80x9cbest casexe2x80x9d estimate of the dimension tolerances allowed is given by the relative bandwidth that is 1% for a MDA. These structures typically have sub-nillimeter dimensions that have to be maintained over surfaces of hundreds ofsquare millimeters. This leads to fabrication tolerances in the micron range that are not achievable with standard low cost readily available technologies.
Accordingly, the present invention addresses a method to automatically manufacture MDAs while using low tolerance parts available at low cost.
The present invention discloses an apparatus and method for manufacturing a magnetic dipole antenna employing one or more spacers. The basic antenna is composed by three plates that could be of any form. The antenna could have some features such as holes or other placing features but not necessarily. In one embodiment, a magnetic dipole antenna (MDA) has three plates, where each plate has holes for inserting one or more spacers through the bottom and middle plates. The distance between the top plate and the middle plate of the magnetic dipole antenna determines the operational frequency. A feeding structure, e.g. a coaxial cable, is attached to the magnetic dipole antenna for measuring the resonant frequency.
A tuning machine, either manual or automated, for adjusting the separation between the top and middle plates or planes using spacers as actuators. Each spacer has an external body surface and an internal hollow core, where the external body surface contains apertures. After a desirable separation between the top and middle plates is achieved, as determined by a test measurement, the spacers are secured by injecting adhesive through the internal hollow core that extends to the apertures in the external body surface.
Other structures and methods are disclosed in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims.